Apparatus for operating airship-shed doors



May 11 ,1'926. 1,584,172

L. G. FISCHER ET AL I APPARATUS FOR OPERATING AIRSHIP SHED DOORS FiledJune 9. 1920 I 4 Sheets-Sheet 1 JO 7? I? a; A E 15 I 76 v wwntoz 5. q I

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L. G. FISCHER ET AL APPARATUS FOR OPERATING AIRSHIP' SHED DOORS May 111926.

Filed- June 9. 1920 4 Sheets-Sheet 2 3 vwe ntoz f May 11 192s. 1,584,172

L. G. FISCHER ET AL APPARATUS FOR OPERATING AIRSHIR SHED DOORS FiledJune 9." 1920 4 Sheets-Sheet 3 3 nozuko'a May 11 1926.

L. G FISCHER ET AL APPARATUS FOR OPERATING AIRSHIP SHED DOORS Fi ledJune 9. 1920 noentoz fittozmqs,

My ER Witness Patented May 11, 1926.

UNITED stares hATET OFFICE.

LOUIS GUSTAV FISCHER, OI? CAMP HILL, AND GEORGE HELPER/T, OF HARRIS-BURG, PENNSYLVANIA, ASSIGNORS, BY MESNE ASSIGNMENTS, T0 BETHLEHEM STEELCOMPANY, A CORPORATION OF DELAWARE.

APPARATUS FOR OPERATING AIRSI-IIP-SI-IED DOORS.

Application filed June 9, 1920. Serial No. 387,777.

This invention relates to mechanism for moving heavy bodies alongtrackways and it relates particularly to mechanism of this characteradapted for use in connection with airship shed doors. The doors forclosing the entrances to airship sheds are often of such large size andgreat weight that it is impossible to move them by manual means within ashort period of time, even when two half-doors are used instead of asingle large door, to close one end of the shed. As it is essential thatsuch doors are openable and closable quickly, power devices are commonlyemployed to effect this result, such as motors mounted on the doors invarious places, steam engines having winding drums for cables which aresecured to the doors, thrust rods or beams with suitable operatingmeans, and other mechanisms of such character.

The various opening and closing mechanisms heretofore designed orsuggested have been expensive to install and operate, cumbersome, andunsightly, and objects of this inventionare, to provide a mechanism ofthis class which is comparatively inexpensive, which is compact,conveniently located, and which presents a neat and attractiveappearance. More specifically stated the invention resides-in novelmechanism for moving an airship shed door which comprises a rack rigidlysecured to the door, a pinion or plurality of pinions meshing with therack and driven by a common power element and, when a plurality ofpinions are used, equalizing gearing interposed between the pinions andpower element for the purpose of equalizing the forces exerted by thepinions on the rack. This arrangement permits a rack of small width tobe used even when great driving force must be exerted thereon, thussaving in the initial cost of the mechanism and the operation and repaircosts. One embodiment of the invention will be dis closed in thefollowing description when taken in connection with the accompanyingdrawings in which:

Figures 1 and 1 taken together illustrate in end elevation one of thedoors, positioned 1n front of the entrance of an airship shed andshowing in section the pit containing the door operating mechanism;

Figure 2 is a plan view of the heavy base portion of a door positionedin front of an airship shed showing the location of the door operatingmechanism, extreme end portions of a second door and a second operatingpit being also shown; I

Figure 3 is a plan View of the pit contain ing the door operatingmechanism to a larger scale, and showing the mechanism in position;

Figure 4 is a section on the line id of Figure 3; a

Figure 5 is a section on the line 5-5 of Figure 3, but showing theentire mechanism for manually operating the door, a portion of which isomitted in Figure 3.

In the drawings the superstructure of the door and many of its detailshave been omitted, but it will be apparent that a steel frame andreinforced concrete base door of this character, which may be severalhun dred feet tall and several hundred feet wide, will be of greatweight and, even though mounted upon trucks, will be extremely difficultto move. The doors whether full or half. size, are necessarily largeinasmuch as it is desired to have the ends of the airship shed entirelyunobstructed for the free entrance and exit of airships only slightlysmaller in diameter than the width of the shed itself.

In the drawings the front of the shed is indicated at 10 and its centerline is indicated by the broken line 11,shown in Figure 2. Two doors areprovided, one on each side f the center line, which are mounted upontrucks and adapted to be rolled aside in opposite directions to open theshed entrance for the passage of airships. As these doors are exactlysimilar only one is completely illustrated in the drawings and thiscomprises a framework base, preferably counterweighted, and a frame ortruss like superstructure to the building face of which is attached theweather proof siding, as diagrammatically I are located supportingtrucks having wheels 12 adapted to roll on trackways 13 which are'parallel to" the" shed front.

Midway between the trackways'the door is provided with a heavy girder orbeam 14 which is parallel to the trackways and shed front and supportson itslower surface the rack 14 which extends from end to end "thereof.Upon'the' teeth of this rack are exerted all of the forces necessary inmoving thedoor, and the rack and its supporting beam are thereforedesigned and constructed in a substantial manner.

Located at short distance beyond the side wall of the shed and betweentracks 18, is the pit P which contains the mechanism for operating thedoor. Thispit preferably has heavy concrete walls with horizontal wingsor extensions, clearly illustrated in Figures 1, 3 and 4c, thehorizontal wings or extensions providing additional bearing surface sothat the reaction of the force exerted upon, the door by the machinerycontained in the pit willnot overturn the foundation upon which themachines are mounted.

The door operating mechanism' comprises essentially two pinions 15 eachof which .meshes with the teeth of rack 14, the pinions being operatedby a single motor 16 through pinion 17, differential gearing G, worms18, 18, mounted on shafts 19, 19, and worm wheels 20, 20, fixed 011 theshafts 21, 21 on which the pinions 15 are secured.

The differential gearing G comprises the usual ring gear 22, planetgears 23, 23, and sun gears 24, 24c mounted respectively on the shafts19, 19. Theuse of this differential gearing insures that each of thepinions 15 will exert the same force on the rack. One particularadvantage of this construction is that, by the provision of two pinionsacting upon a single rack at different points, it is possible to greatlyreduce the necessary width of the rack, which is necessarily of suchwidth that its teeth give the requisite bearing surface for the pinionteeth. By multiplying the number of pinions ample bearing area isprovided by a narrow rack. While the use of difierential gearing ispreferred, for equalizing the pressure of the pinions on the rack thisresult may be ebtained by other means as for instance. multiple motors.

lieans 15 provided for operating the mechanism manually incasethe motorshould be inoperative, for any reason. This means comprises a rotatableshaft 25 provided at one end with a bevel gear 26 which may be broughtinto mesh with a bevel gear 27 on the motor shaft when desired, andhaving at its other end a bevel gear 28 meshing with a bevel gear 29 onthe lower end of a capstan stem, the upper part of which is above theground level and is provided with capstan bars 30 by means of which itmay be manually rotated. The motor may be disconnected from the pinion17 when the doors-are being manually moved. This means-of operating thedoors is muchslower than when the motor is employed. If a steam engineor other external motor provided with a winding drum, or a locomotive ona nearby track, is available, a cable may be wrapped around-the drum 31of the capstan, which will be rotated when the cable is unwound.

It will'beunderstood that each of the doorsis similar and has similaroperating mechanism, and it will be also understood that the design andarrangement of parts of the apparatus may be altered within the limitsof the invention and we do not therefore, limit ourselves to theexactform shown and described.

Having thus described the invention what is claimed as new and desiredto be secured by Letters Patent is:

1. In mechanism of the class described, the combination with a doorhaving a rack, of means for operating the door comprising aplurality ofpinions in engagement with said rack, a source of power, and powertransmission mechanism between the source of power and the pinionsincluding'means for equalizing the forces exerted by the pinions on therack. I

2. In mechanism of the class described, the combination with a doormounted on rollers and having a rack extendinglongitudinally thereof, ofmeans for operating the door comprising a plurality of pinions inengagement with said rack, a driving member and diiferential'gearingbetween the driving member and the pinions. y

3. Inmechanism of the class described, the combination with a doorhavinga rack, of means for moving said door comprising two pinionsrotatably mounted on stationary axles and engaging'said rack, a motor,and means operatively connecting said motor and pinions, said meansincluding a device for equalizing the forces exerted by said pinions onthe rack.

4. In mechanism of the class described, the combination with a doorhaving a rack secured thereto, of means for moving said door comprisingtwo pinions rotatably mounted on stationary axles and engaging saidrack, a motor, and gearing operatively connecting said motor and pinionsincluding differential gearing for equalizing the forces exerted by saidpinions on the rack.

5. The combination, with a door, of

means for moving the door comprising a rack carried by the door; aplurality of pinions spaced longitudinally of and engaging the rack; adriving member; differential gearing including a pair of driven gears,planet pinions engaging the driven gears, and a carrier for the pinions;means for connecting the carrier With the driving member; and means forconnecting the driven gears to the respective pinions. 10

In testimony whereof We afiix our signetures.

MEIER GEORGE I-IILPERT. LOUIS GUSTAV FISCHER.

